Spent some time replacing the 2004/10/10 DirectoryIndex icons with a new set. [Spoiler: they are from the Google Noto Sans Unicode 17.0 set.] They only cover the most used files so far, and this also required a cleanup and restructuring of set icons.

Lesser used files still use the v2 icon set from 2004/10/10 (called http-icons.tgz), and the only one used from the original icon set is the blank icon.

Oh, and this server finally uses transparent .png instead of .gif for the icons.